A bipartisan group of lawmakers has contacted the Department of Justice over what they believe is “potentially criminal conduct by Amazon.”

Amazon has been under increasing scrutiny for what some perceive as monopolistic practices. During investigation into Amazon’s practices, lawmakers believe some of Amazon’s executives were deceitful, intentionally misleading members of Congress.

A bipartisan group of lawmakers — Jerrold Nadler, David N. Cicilline, Ken Buck, Pramila Jayapal, and Matt Gaetz — have written Attorney General Merrick Garland to express their concerns.

Last Congress, the U.S. House of Representatives’ Committee on the Judiciary (Committee) conducted an extensive investigation into competition in digital markets. During that investigation, and in follow-up inquiries, Amazon engaged in a pattern and practice of misleading conduct that suggests it was “acting with an improper purpose” “to influence, obstruct, or impede” the Committee’s investigation and inquiries.

The lawmakers also allege that Amazon has failed to cooperate by refusing to turn over documents the lawmakers requested.

Without producing any evidence to the contrary, Amazon has left standing what appear to be false and misleading statements to the Committee. It has refused to turn over business documents or communications that would either corroborate its claims or correct the record. And it appears to have done so to conceal the truth about its use of third-party sellers’ data to advantage its private-label business and its preferencing of private-label products in search results—subjects of the Committee’s investigation. As a result, we have no choice but to refer this matter to the Department of Justice to investigate whether Amazon and its executives obstructed Congress in violation of applicable federal law.

This latest issue could spell major problems for the e-commerce giant, especially if the DOJ follows through on the lawmakers’ request and launches an official investigation.